Okay, so I came up with the idea to do this fanfic while watching episodes of Star vs. The Forces of Evil and Miraculous Ladybug. And I realized that both shows had a lot in common, so why not blend the two into a crossover fic? :)

Prologue

It was another boring day at the Diaz household. Star Butterfly and her friend Marco Diaz had just come home from the last few minutes of school before spring break. The two of them had plans for the entire vacation, and none of them involved fighting Ludo or his army.

"Ah, this is the life," Marco said, lounging back on his chair. "Nothing but you, me, and 5 days of nothing but relaxation."

"You said it," agreed Star Butterfly, the fourteen-year-old princess of Mewni. Star and Marco first met at Echo Creek Academy after Star's parents, who were the King and Queen of Mewni, transferred her to Earth so that Star could master her wand. While Star was still not in control of her wand just yet, her wandwork had tremendously improved from when she first started. In fact, at one point, she had managed to defeat an entire brigade of Ludo's henchmen with just one spell.

"Sooooooo . . . what do you want to do?" Marco asked Star.

"We could always call up Pony Head and go on another dimension hopping adventure," Star eagerly suggested.

"Oh boy," Marco said; he knew exactly what was going on in her head: Nothing but a wild night of going to interdimensional clubs, arcades, the likes. The last time that had happened, he had been taken by three men from St. O's who interrogated him about Pony Head. Though the misunderstanding had been cleared up, he was still not looking forward to another episode like that.

"Or," he proposed, "we could go on vacation somewhere."

"Ooh! Ooh! How about Rome?" Star asked eagerly. "I always wanted to be there! Or maybe London? I always wanted to visit Shakespeare's birthplace!"

"Where were you in class?" Marco asked. "He was born in Stratford-upon-Avon!"

"Oh," Star said, a bit disappointed. "But can we still go there?"

"I guess," Marco admitted. "But the thing is, I always wanted to visit Paris."

At the mention of the word "Paris", Star's eyes lit up like Christmas lights. "Well, why didn't you say so? I have been DYING to go there! It's like, one of the places I really looked forward to going to here!"

"There's just one problem," Marco pointed out. Star's happy demeanor deflated a little. "We have a lot of stuff to pack. Not to mention that we need to know how to speak French. I don't suppose that wand of yours has a spell that will allow you to speak a foreign language, does it?"

"I'm sorry, mon ami," Star sighed. "Not that I know of."

"That's a shame," Marco lamented. "Oh well, as least we'll be able to go sightseeing. I have a list of things that I've always wanted to see, like the Arc de Triomphe, the Eiffel Tower . . ."

"And don't forget the Seine River," Star added, beaming at him. "I heard that the place is sooooo romantic."

Marco chuckled. "Okay, we'll see if we can stop by that place on out sightseeing tour."

Just then, Mr. and Mrs. Diaz stopped by in the living room accompanied by a few laser puppies that Star accidentally conjured up on her first day here. At first, Marco had found them extremely annoying, but over time, had come to accept them as a part of his life, much like Star.

"Mom, Dad," Marco started, "our school is having spring break, and I wondering if we can go to Paris soon."

Mr. Diaz chuckled. "I'm sorry, but we never booked any flights for vacation. Maybe we can go this summer if both your mom and I are available then."

"Or," Star proposed eagerly, "I could always use the dimensional scissors to get us there in a jiffy." She took out the dimensional scissors, which, to the eyes of someone inexperienced, looked like a regular pair of scissors.

"Huh. Why didn't I think of that," Mr. Diaz said. "Well, in that case, I suppose we could, if we had everything packed and ready by tomorrow."

"AWESOME!" Star yelled with glee, jumping off the walls to convey her excitement. "We're going to have so much fun!" She gave Marco a bear hug and bounced upstairs to get her stuff ready. Marco looked after her, smiling in satisfaction.

It was nighttime in Paris. Marinette Dupain-Cheng, a plucky fourteen-year-old high school student with blue hair, had just come back from a long day fighting another one of Hawk Moth's akumas. And as always, she lamented that she never got a chance to speak her crush Adrien Agreste, the son of her favorite fashion designer Gabriel Agreste. Although she could not help but wonder that her sidekick, Cat Noir, looked an awful lot like him . . .

She went upstairs to her bedroom, her energy totally spent. Her companion, a ladybug kwami named Tikki, floated by her side as she did so.

"Whew! Man, that sure was hard work, Tikki," she breathed.

"You can say that again," Tikki said. Like her human friend, the kwami too was tired. In fact, the first thing that Marinette did was fall straight onto her bed like a sack of yams. It was the weekend, and most of Marinette's friends would normally be out partying or hanging out. But unfortunately, Marinette had no such social life, and her social circle was limited to her parents, a few classmates from school, Alya, and perhaps Adrien. But other than that, not much was going in the way for her.

"Tikki?" Marinette asked her Kwami.

"Yeah, Marinette?"

"You ever wish that sometimes, you could have a bit more . . . adventure in your life?"

"Why do you ask that?"

"I don't know," Marinette sighed. "It's just . . . All I have to look forward to is nothing but school, fighting akumas, school, crushing on Adrien, and school. I want some more action in my life. Just once, I'd like to meet new people and learn about their lives. That would make my ordinary life a bit more exciting. You know?"

"Yeah," Tikki said. "I know how that feels. But trust me, I have a feeling that you will meet someone new down the road."

"What makes you say that?" Marinette asked, curious.

"Things like this often happen when we least expect it," the ladybug kwami said sagely. "But it's best we let them take their course."

"Well," Marinette said to her companion, "good night, Tikki." She turned off the lights and fell asleep.

Elsewhere in Paris, in his large, comfortable estate in the outskirts of Paris, Adrien Agreste was feeling discontent as well. As his father would not allow him to go party with his friends like every other Parisian kid on a Friday night, he was stuck at home and forced to do nothing. Just once, he wished he could have a normal life like everyone else. But as Cat Noir, he would be very lucky to have even one day without fighting any akumas. In fact, he and his crush/sidekick Ladybug had just defeated yet another akuma who had tried to destroy an environmental factory in Paris. And yet he got the feeling that he had seen her somewhere before . . .

"Hey Plagg," he said, plopping down on his bed. "Do you ever wish that we could have, you know, more life outside these walls and empty spaces?"

Plagg, Adrien's cat kwami, didn't answer. He was too busy munching down on smelly cheese to even think of anything else. At last, he finished his last bite and gulped. "I don't know. Why would you ask?"

"Because just for one day," he said, "I'd like to meet some new people. Don't get me wrong, I like my schoolfriends and all, and I enjoy fighting alongside Ladybug, but I noticed that there appears to be a bit of a repetitive streak: I go to school, someone gets akumatized, I say 'Plagg, claws out!', I help Ladybug defeat the akuma, and before I get a good look and find out who Ladybug really is, she disappears." He sighed in discontent. "Just once, I would like a break from this. I wish I could meet new people and share adventures with them. What more is out there?"

"Believe me," the cat kwami said, "you might as well ask the bottom of your shoes for the answers."

Adrien sighed again. "All right, I guess I will call it a night. Who knows? Maybe I will find what I'm looking for."

And so, both Marinette and Adrien drifted off into sleep, unaware that in a few hours, their whole lives would change forever.

(~)

MetaLord395 presents . . .

Based on characters by Daron Nefcy and Thomas Astruc

(sing to the Miraculous Ladybug theme song)

Star(speaking):

In the daytime, I'm Star Butterfly,

Seemingly a normal girl with a normal life

But what they don't know is that I have a secret

Of which only Marco is aware.

Starring:

Eden Sher as Star Butterfly

(singing)

I live a life, that's full of fun,

It keeps me sharp and on the run

Adam McArthur as Marco Diaz

When evil comes, I find a way

To use my powers and save the day

Alan Tudyk as Ludo, King Butterfly

Oh oh oh,

Life's got me spinning round

Artt Butler as Mr. Diaz

Nia Vardalos as Mrs. Diaz

Oh oh oh

He's got me off the ground

Christina Vee as Marinette Dupain-Cheng/Ladybug

Oh oh oh

And when the night comes up,

You'd better stick around

Bryce Papenbrook as Adrien Agreste/Cat Noir

Chorus:

I'm Star Butterfly

Flying so high

Mela Lee as Tikki

Max Mittelman as Plagg

Keith Silverstein as Hawk Moth, Gabriel Agreste

And I feel like I could reach the sky

I'm Star Butterfly

Just swinging by

I don't mind if you say to me "Hi"

Carrie Keranen as Alya Cesaire

Marco:

The name's Marco, I'm a bad boy

If you say otherwise, I'll be annoyed

Ben Diskin as Nino Lahiffe

She is my "Star", she's my best friend

And we'll stay that way 'til the end

Marieve Herington as Sabrina Raincomprix

Oh oh oh

She's got me spinning 'round

Selah Victor as Chloe Bourgeois

Oh oh oh

My life is upside down

Grey DeLisle as Queen Butterfly

Oh oh oh

And when the lights go out

We'll always be around

Chorus 2x

Marco:

It's Star Butterfly, flying so high!

Ohhh!

Dorothy Fahn as Sabine Cheng

She's Star Butterfly, just swinging by

and Christopher Smith as Tom Dupain

She doesn't mind if you tell "Hi"

Based on the TV shows "Star vs The Forces of Evil" and "Miraculous: Ladybug and Cat Noir"

It's Star Butterfly!

(~)

MIRACULOUS LADYBUG VS. THE FORCES OF EVIL